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Mitigating the risk of solar geoengineering

Mitigating the risk of solar geoengineering | Amazing Science |
Aerosols could cool the planet without ozone damage | To halt the rise of global temperatures, Harvard researchers are looking at solar geoengineering, which would inject light-reflecting sulfate aerosols into the stratosphere to cool the planet.


The planet is warming at an unprecedented rate, and reducing emissions of greenhouse gases alone is not enough to remove the risk. Last year’s historic Paris climate agreement set the goal of keeping global temperatures no higher than 1.5 degrees Celsius above preindustrial levels. Emission reductions will be central to achieving that goal, but supplemental efforts can further reduce risks.


One drastic idea is solar geoengineering — injecting light-reflecting sulfate aerosols into the stratosphere to cool the planet. Researchers know that large amounts of aerosols can significantly cool the planet; the effect has been observed after large volcanic eruptions. But these sulfate aerosols also carry significant risks. The biggest known risk is that they produce sulfuric acid in the stratosphere, which damages ozone. Since the ozone layer absorbs ultraviolet light from the sun, its depletion can lead to increased rates of skin cancer, eye damage, and other adverse consequences.


Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have identified an aerosol for solar geoengineering that may be able to cool the planet while simultaneously repairing ozone damage. The research is published in the Proceedings of the National Academy of Sciences.


“In solar geoengineering research, introducing sulfuric acid into the atmosphere has been the only idea that had any serious traction until now,” said David Keith, the Gordon McKay Professor of Applied Physics at SEAS and professor of public policy at the Harvard Kennedy School, the first author of the paper. “This research is a turning point and an important step in analyzing and reducing certain risks of solar geoengineering.”

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Greenland's ice sheet more vulnerable to melting, research finds

Greenland's ice sheet more vulnerable to melting, research finds | Amazing Science |
Worrying news for sea level rise: the massive ice sheet melted several times between ice ages, meaning it's less stable and less likely to survive the rapidly rising temperatures of global warming.


Scientists found that Greenland rocks now buried under 10,000 feet of ice were ice-free for long stretches during the past 1.4 million years, leading them to predict the Greenland Ice Sheet could melt more suddenly than previously believed. That could raise global sea level far beyond current projections over the next few centuries, including recent estimates from the Intergovernmental Panel on Climate Change, according to a new study published Wednesday in the journal Nature. The research challenges the prevailing idea that the ice sheet remained relatively intact during the recent geological past, showing even the thickest ice had vanished during warm periods between ice ages.


Columbia University paleoclimatologist Joerg Schaefer, who co-authored the study, said the findings show the Greenland Ice Sheet may be much less stable than scientists thought.

"Over the last 15 years, it looked like we wouldn't have to worry too much about the Greenland ice sheet melting too fast," Schaefer said. "Most of the climate models treated it as a solid ice cube sitting on bedrock. With climate warming, it melts off the top, but it takes a long time. Compared to other ice sheets like West Antarctica, is looked pretty strong and resilient to warming."

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West Antarctic ice shelf breaking up from the inside out

West Antarctic ice shelf breaking up from the inside out | Amazing Science |
A key glacier in Antarctica is breaking apart from the inside out, suggesting that the ocean is weakening ice on the edges of the continent.


The Pine Island Glacier, part of the ice shelf that bounds the West Antarctic Ice Sheet, is one of two glaciers that researchers believe are most likely to undergo rapid retreat, bringing more ice from the interior of the ice sheet to the ocean, where its melting would flood coastlines around the world.


A nearly 225-square-mile iceberg broke off from the glacier in 2015, but it wasn't until Ohio State University researchers were testing some new image-processing software that they noticed something strange in satellite images taken before the event.


In the images, they saw evidence that a rift formed at the very base of the ice shelf nearly 20 miles inland in 2013. The rift propagated upward over two years, until it broke through the ice surface and set the iceberg adrift over 12 days in late July and early August 2015. They report their discovery in the journal Geophysical Research Letters.


"It's generally accepted that it's no longer a question of whether the West Antarctic Ice Sheet will melt, it's a question of when," said study leader Ian Howat, associate professor of earth sciences at Ohio State. "This kind of rifting behavior provides another mechanism for rapid retreat of these glaciers, adding to the probability that we may see significant collapse of West Antarctica in our lifetimes."

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World Population Growth

World Population Growth | Amazing Science |

The UN calculates that there are more than 7 billion living humans on Earth, yet 200 years ago we numbered less than 1 billion.1 Recent estimates suggest that 6.5 percent of all people ever born are alive right now.2 This is the most conspicuous fact about world population growth: for thousands of years, population grew only slowly, but in recent centuries it has jumped dramatically. Between 1900 and 2000 the increase in world population was three times greater than the entire previous history of humanity– an increase from 1.5 to 6.1 billion in just 100 years.


A picture of world population in the very long-run fits the pattern of exponential growth (when a population grows exponentially the rate of growth is proportional to the size of the population). Yet an empirical observation of how growth rates have developed in the course of the last century reveals that this pattern no longer holds. The annual rate of population growth has recently been going down. A long historical period of accelerated growth has thus come to an end; the annual world population growth rate peaked in 1962, at around 2.1%, and has come down to almost half since.3


Based on these observations, world history can be divided into three periods marked by distinct trends in population growth. The first period (pre-modernity) was a very long age of very slow population growth. The second period, beginning with the onset of modernity (with rising standards of living and improving health) and lasting until 1962, had an increasing rate of growth. Now that period is over, and the third part of the story has begun; the population growth rate is falling and will likely continue to fall, leading to an end of growth towards the end of this century.

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Scientists say climate change wiped out an entire underwater ecosystem

Scientists say climate change wiped out an entire underwater ecosystem | Amazing Science |
An Australian kelp forest vanished with a slight warming of ocean temperatures and an incursion of tropical fish.


We’ve heard a lot lately about the destruction of tropical coral reefs brought on by a warming climate. And that’s a big deal — corals are the lynchpin of entire undersea ecosystems. When they go, the damage reverberates widely and ultimately, even people pay the price.


But something similar has been happening to corals’ more temperate cousins in many locations: Forests of kelp. These swaying seaweeds, too, anchor communities of diverse types of fish and other living organisms and, in turn, provide great value to humans through their contribution to fisheries. And recently, there has been some very troubling news for kelp. One forest was wiped out off the southwestern coast of Australia by extremely warm temperatures in 2011, an event that scientists called a “rapid climate-driven regime shift.” More recently, there has been massive death of giant kelp around Tasmania as well.


And now, new research in the Proceedings of the National Academy of Sciences demonstrates another way that a changing climate can devastate kelp. Adriana Vergés of the University of New South Wales in Sydney and her colleagues at institutions in Australia, Spain, and Singapore used underwater cameras to study kelp forests around the Solitary Islands, along the eastern Australian coast between Sydney and Brisbane.


This region is what Vergés calls “a famous place for being a tropical-temperate transition zone. We went there because that’s where we thought, if there’s something that is happening to the kelp, that is climate mediated, this is where it is going to be happening,” she said.

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Why scientists are so worried about sea-level rise in the second half of this century

Why scientists are so worried about sea-level rise in the second half of this century | Amazing Science |
Seas could rise by a foot off the U.S. east coast by 2040 if we continue at a high level of emissions.


Even as negotiators meet in Marrakech, Morocco to take the next steps to avert dangerous human-caused climate change — and, even as the U.S. decides whether or not to elect a president who is skeptical it is happening — a new study has highlighted the sharp stakes involved, particularly when it comes to the ongoing rise in global sea level and the dramatic but uneven way in which it could affect the world’s coastlines.


The goal of the Paris climate agreement is to hold the planet’s temperature rise to “well below” a 2 degrees Celsius (3.6 degrees Fahrenheit) increase above what it was in pre-industrial times. We’ve already seen about a 1 degree Celsius (1.8 degrees Fahrenheit) increase since then.


But the new research just published in the Proceedings of the National Academy of Sciences notes that if we stay on a current, high-emissions pathway and do not achieve the cuts that the Paris agreement seeks to institutionalize, then we could hit 2 degrees Celsius by 2040 or so. For the planet’s sea level, this would mean over a half-foot rise averaged around the globe, in comparison with average sea levels from 1986 to 2005. The sea-level increase, however, would be far worse in certain places, such as the U.S. East Coast, where it could be over a foot.


And that’s just the beginning. Assuming we still don’t reform our ways, the 40 years after 2040 could then see another sharp 2 degree increase in temperatures — to 4 degrees Celsius — and another dramatic surge in sea level, culminating in a rise of 2 feet averaged across the globe, or more if we’re unlucky. The study finds that by 2100, New York could see a sea level rise of more than 3.5 feet.


“Basically we spent 200 years to warm our planet by 2 degrees, and then we will do it in 40 years time, this shows a completely different scale of what’s going on,” said Svetlana Jevrejeva, the lead author of the study and a researcher at the National Oceanography Centre in the United Kingdom, in describing the scenario presented in the study. Jevrejeva completed the work with researchers at institutions in the U.K., the Netherlands, Denmark, China, and Finland.

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70% Of Earth's Fresh Water Is Frozen

70% Of Earth's Fresh Water Is Frozen | Amazing Science |

About 71% of the Earth is covered in water. Most of that is in oceans, rivers, and lakes, but some is frozen in the Earth's two ice sheets. Those ice sheets, which cover most of Greenland and Antarctica, only contain 2% of the world's total water supply, but a whopping 70% of the Earth's fresh water.


Scientists estimate that if the Antarctic Ice Sheet—the larger of the two—melted, sea level would rise by around 60 meters (200 feet). Not only that, but it could affect the weather: a study showed that less sea ice in the Arctic causes rainier summers in western Europe, and another study suggests that it's causing more extreme heat waves in the United States and elsewhere. And counterintuitively, melting ice also causes more melting ice.


A 2016 study found that a shrinking in the Greenland Ice Sheet causes what are known as "blocking events," where high-pressure systems park themselves on top of one area for days or even weeks. This brings warm, moist air that heats the surface below and causes even more ice to melt. Explore the relationship between polar ice and climate change in the videos below.

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A new 30,000-y-old giant virus infecting Acanthamoeba found

A new 30,000-y-old giant virus infecting Acanthamoeba found | Amazing Science |

The saga of giant viruses (i.e. visible by light microscopy) started in 2003 with the discovery of Mimivirus. Two additional types of giant viruses infecting Acanthamoeba have been discovered since: the Pandoraviruses (2013) and Pithovirus sibericum (2014), the latter one revived from 30,000-y-old Siberian permafrost.


A group of scientists now describe Mollivirus sibericum, a fourth type of giant virus isolated from the same permafrost sample. These four types of giant virus exhibit different virion structures, sizes (0.6–1.5 µm), genome length (0.6–2.8 Mb), and replication cycles. Their origin and mode of evolution are the subject of conflicting hypotheses.


The fact that two different viruses could be easily revived from prehistoric permafrost, even after 30,000 years of being frozen, should be of concern in a context of global warming.

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The Rabbs' Tree Frog Just Went Extinct

The Rabbs' Tree Frog Just Went Extinct | Amazing Science |

The last known member of his species has died at Atlanta Botanical Garden.


Known as “Toughie,” the tiny male frog, originally from Panama, spent the past few years living by himself at Atlanta Botanical Garden. The species has not been observed in the wild since 2007, just two years after it was first discovered by scientists. Toughie’s death follows four and a half years after another Rabbs’ tree frog died at Zoo Atlanta. That frog was euthanized in 2012 after its health began to decline.


Both of these Rabbs’ tree frogs were collected in Panama while scientists were there investigating the deadly chytrid fungus, which has devastated amphibian populations in that country and around the world. Although no signs of wild Rabbs’ tree frogs have shown up in the past nine years, at least one scientist still held out hope they might one day be found again. “The habits of this genus can make them extremely difficult to find if they remain high up in the trees,” says Jonathan Kolby, director of the Honduras Amphibian Rescue and Conservation Center.


“Being that this species breeds in tree cavities up in the canopy, I would hope that this behavior offers some protection from exposure to chytrid fungus, although the species was reported to have become much less common after the arrival of chytrid in the region.” Still, the likelihood remains that the Rabbs’ fringe-limbed tree frog is now truly gone. That’s notable, not just for the extinction, but for the circumstances around Toughie’s life.


Extinctions, you see, are very rarely witnessed by humans. Instead, they tend to be discovered years or even decades after the last member of a species gave up the fight. The Rabbs’ tree frog was a rare exception. For the past four and a half years, Toughie has been a very public ambassador for his lost species, and for all of the frog species going extinct around the world during the current amphibian extinction crisis. How many thousands of people who walked by his enclosure at Atlanta Botanical Garden felt the pull and gravity of his inevitable extinction? As the organization posted today on Facebook, “He will be missed by Garden staff and visitors alike.”

Via Kathy Bosiak
Kacy Solera's comment, October 4, 2016 6:54 PM
This article tells about how the last known Rabb Fringlimbed tree frog which is also known as toughie died in the Atlanta Botanical Garden. This rare frog originates from panama and really haven't been seen around for a while so when the last known frog died many scientists were quite sad and hoped to be found again soon. I chose this story because it saddens me that these poor animals keep going extinct.
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Climate change could push risk of ‘megadrought’ to 99% in Western US

Climate change could push risk of ‘megadrought’ to 99% in Western US | Amazing Science |

A megadrought spanning several decades could be almost certain to hit the American southwest this century if greenhouse gas emissions are not curbed, a new study says.


Rising temperatures will “load the dice” in favor of a megadrought in the region, the researchers say. Combined with a decline in rainfall, warming conditions could put risk levels at 99% for much of the region, the study finds, while moderate increases in rainfall would still leave risk levels above 70%.


But there is a “glimmer of hope” another scientist tells Carbon Brief. The study also shows that keeping global temperature rise to no more than 2C above pre-industrial levels would cut this risk by half.

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Earthquakes Will Be as Predictable as Hurricanes Thanks to AI

Earthquakes Will Be as Predictable as Hurricanes Thanks to AI | Amazing Science |

Companies like GeoCosmo and Terra Seismic are working on earthquake prediction algorithms that integrate lithosphere-atmosphere-ionosphere coupling data with related indicators like changes in ground water level and ground conductivity.


GeoCosmo has accurately forecast twenty different earthquakes in North and South America up to seven days before they happened. The company is integrating a cellphone app into its system; called the Cellphone Sensor Project, the app sends users lightweight bursts of data that allow phones’ magnetometers to collect and send data about the strength of magnetic fields in their locations. Their goal is to be able to leverage one billion cellphone magnetometers in the most seismically active regions of the world.


When the Tohoku earthquake hit, Tokyo residents received a one-minute warning via Japan's earthquake early warning system. High-speed trains and factory assembly lines were stopped and buildings were evacuated. Nonetheless, the death toll according to Japan's National Police Agency was 15,891.


How might this number have shrunk if the Japanese people had had three days or a week to prepare instead of one minute? Granted, in this case, a large portion of the death toll was caused by the tsunami, and even if we can forecast an earthquake we won’t be able to predict all of its byproducts. But many more lives will be saved and disasters like Fukushima averted as physics and artificial intelligence refine their ability to accurately predict earthquakes.


GeoCosmo Chairman and Chief Scientist Friedemann Freund says, “The total energy released during a magnitude 9.0 earthquake is equivalent to the explosion of two million atomic bombs of the Hiroshima class simultaneously. I find it incomprehensible from a physics perspective that a process that releases so much energy in the moment of rupture will not express itself in some recognizable way before the rupture occurs.”

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Earth's Carbon Dioxide Passes the 400 PPM Threshold –Maybe Permanently

Earth's Carbon Dioxide Passes the 400 PPM Threshold –Maybe Permanently | Amazing Science |

Carbon dioxide levels often hit lows in September, but now remain above a crucial benchmark. 


In the centuries to come, history books will likely look back on September 2016 as a major milestone for the world’s climate. At a time when atmospheric carbon dioxide is usually at its minimum, the monthly value failed to drop below 400 parts per million. That all but ensures that 2016 will be the year that carbon dioxide officially passed the symbolic 400 ppm mark, never to return below it in our lifetimes, according to scientists.


Because carbon pollution has been increasing since the start of the Industrial Revolution and has shown no signs of abating, it was more a question of “when” rather than “if” we would cross this threshold. The inevitability doesn’t make it any less significant, though.


September is usually the month when carbon dioxide is at its lowest after a summer of plants growing and sucking it up in the northern hemisphere. As fall wears on, those plants lose their leaves, which in turn decompose, releasing the stored carbon dioxide back into the atmosphere. At Mauna Loa Observatory, the world’s marquee site for monitoring carbon dioxide, there are signs that the process has begun but levels have remained above 400 ppm.

Via Kathy Bosiak
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Global warming contributed to unprecedented 2015 toxic algal bloom

Global warming contributed to unprecedented 2015 toxic algal bloom | Amazing Science |

A study led by researchers at the University of Washington and the National Oceanic and Atmospheric Administration connects the unprecedented West Coast toxic algal bloom of 2015 that closed fisheries from Southern California.


"We have toxic algae events that result in shellfish closures off the Washington and Oregon coast every three to five years or so, but none of them have been as large as this one," said lead author Ryan McCabe, a research scientist at the UW's Joint Institute for the Study of the Atmosphere and Ocean, a collaborative center with NOAA. "This one was entirely different, and our results show that it was connected to the unusual ocean conditions."


The study is now online in Geophysical Research Letters, a journal of the American Geophysical Union. "This paper is significant because it identifies a link between ocean conditions and the magnitude of the toxic bloom in 2015 that resulted in the highest levels of domoic acid contamination in the food web ever recorded for many species," said co-author Kathi Lefebvre, a marine biologist at NOAA's Northwest Fisheries Science Center. "This is an eye-opener for what the future may hold as ocean conditions continue to warm globally."


The authors found that the 2015 harmful algal bloom, which set records for its spatial extent and the level of toxicity, was dominated by a single species of diatom, Pseudo-nitzschia australis, normally found farther south off California.


Warm water not only allowed this species to survive, it also created an environment favoring its growth. By early 2015 the warm "blob" had moved toward shore and spread all along the West Coast. Warmer water creates less dense surface water that is more likely to stay floating on the surface, where it can become depleted in nutrients.


Previous laboratory studies by co-author William Cochlan of San Francisco State University showed that P. australis can take up nitrogen very quickly from a variety of sources, and appear to outcompete other, nontoxic phytoplankton in nutrient-depleted warm water.

Lauren Zahn's curator insight, October 3, 2016 11:02 AM
As our climate increases in temperature, our coastal areas are being greatly effected and this is showing in the toxic algal blooms popping up along the West Coast.
Summer Lee's comment, October 3, 2016 11:08 AM
I almost did my capstone research on toxic algae blooms! They're so interesting and it's crazy to see that they're popping up along the West Coast because we're so used to seeing them on the East Coast.
Victoria Gab Sales's curator insight, October 12, 2016 10:52 PM


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Surge in methane emissions threatens efforts to slow climate change

Surge in methane emissions threatens efforts to slow climate change | Amazing Science |
Global concentrations of methane, a powerful greenhouse gas and cause of climate change, are now growing faster in the atmosphere than at any other time in the past two decades.


That is the message of a team of international scientists in an editorial to be published 12 December 2016 in the journal Environmental Research Letters. The group reports that methane concentrations in the air began to surge around 2007 and grew precipitously in 2014 and 2015. In that two-year period, concentrations shot up by 10 or more parts per billion annually. It's a stark contrast from the early 2000s when methane concentrations crept up by just 0.5 parts per billion on average each year. The reason for the spike is unclear but may come from emissions from agricultural sources and mainly around the tropics - potentially from farm sites like rice paddies and cattle pastures.

Scientists involved in the editorial will discuss these trends at a session during the fall meeting of the American Geophysical Union (AGU) in San Francisco on Tuesday, 13 December.


The findings could give new global attention to methane - which is much less prevalent in the atmosphere than carbon dioxide but is a more potent greenhouse gas, trapping 28 times more heat. And while research shows that the growth of carbon dioxide emissions has flattened out in recent years, methane emissions seem to be soaring.


"The leveling off we've seen in the last three years for carbon dioxide emissions is strikingly different from the recent rapid increase in methane," says Robert Jackson, a co-author of the paper and a Professor in Earth System Science at Stanford University. The results for methane "are worrisome but provide an immediate opportunity for mitigation that complements efforts for carbon dioxide."


The authors of the new editorial previously helped to produce the 2016 Global Methane Budget. This report provided a comprehensive look at how methane had flowed in and out of the atmosphere from 2000 to 2012 because of human activities and other sources. It found, for example, that human emissions of the gas seemed to have increased after 2007, although it's not clear by how much. The methane budget is published every two to three years by the Global Carbon Project, a research project of Future Earth.

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Global warming will drive the loss of 55 billion tons of carbon from the soil by 2050

Global warming will drive the loss of 55 billion tons of carbon from the soil by 2050 | Amazing Science |
A new global analysis finds that warming temperatures will trigger the release of trillions of kilograms of carbon from the planet’s soils, driven largely by the losses of carbon in the world’s colder


For decades scientists have speculated that rising global temperatures might alter the ability of soils to store carbon, potentially releasing huge amounts of carbon into the atmosphere and triggering runaway climate change. Yet thousands of studies worldwide have produced mixed signals on whether this storage capacity will actually decrease — or even increase — as the planet warms. It turns out scientists might have been looking in the wrong places.


A new Yale-led study in the journal Nature finds that warming will drive the loss of at least 55 trillion kilograms of carbon from the soil by mid-century, or about 17% more than the projected emissions due to human-related activities during that period. That would be roughly the equivalent of adding to the planet another industrialized country the size of the United States.


Critically, the researchers found that carbon losses will be greatest in the world’s colder places, at high latitudes, locations that had largely been missing from previous research. In those regions, massive stocks of carbon have built up over thousands of years and slow microbial activity has kept them relatively secure.


Most of the previous research had been conducted in the world’s temperate regions, where there were smaller carbon stocks. Studies that focused only on these regions would have missed the vast proportion of potential carbon losses, said lead author Thomas Crowther, who conducted his research while a postdoctoral fellow at the Yale School of Forestry & Environmental Studies and at the Netherlands Institute of Ecology.


“Carbon stores are greatest in places like the Arctic and the sub-Arctic, where the soil is cold and often frozen,” Crowther said. “In those conditions microbes are less active and so carbon has been allowed to build up over many centuries. “But as you start to warm, the activities of those microbes increase, and that’s when the losses start to happen,” Crowther said. “The scary thing is, these cold regions are the places that are expected to warm the most under climate change.”


The results are based on an analysis of raw data on stored soil carbon from dozens of studies conducted over the past 20 years in different regions of the world. The study predicts that for one degree of warming, about 30 petagrams of soil carbon will be released into the atmosphere, or about twice as much as is emitted annually due to human-related activities (A petagram is equal to 1,000,000,000,000 kilograms). This is particularly concerning, Crowther said, because previous climate studies predicted that the planet is likely to warm by 2 degrees Celsius by mid-century.

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Captain Cook's detailed 1778 records confirm global warming today in the Arctic

Captain Cook's detailed 1778 records confirm global warming today in the Arctic | Amazing Science |
Passengers simmered in Jacuzzis and feasted on gourmet cuisine this summer as the 850-foot cruise ship Crystal Serenity moved through the Northwest Passage.


But in the summer of 1778, when Capt. James Cook tried to find a Western entrance to the route, his men toiled on frost-slicked decks and complained about having to supplement dwindling rations with walrus meat.


The British expedition was halted north of the Bering Strait by "ice which was as compact as a wall and seemed to be 10 or 12 feet high at least," according to the captain's journal. Cook's ships followed the ice edge all the way to Siberia in their futile search for an opening, sometimes guided through fog by the braying of the unpalatable creatures the crew called Sea Horses.


More than two centuries later, scientists are mining meticulous records kept by Cook and his crew for a new perspective on the warming that has opened the Arctic in a way the 18th century explorer could never have imagined. Working with maps and logs from Cook's voyage and other historical records and satellite imagery, University of Washington mathematician Harry Stern has tracked changes in ice cover in the Chukchi Sea, between Alaska and Russia, over nearly 240 years.


The results, published this month in the journal Polar Geography, confirm the significant shrinkage of the summer ice cap and shed new light on the timing of the transformation. The analysis also extends the historical picture back nearly 75 years, building on previous work with ships' records from the 1850s.


"This old data helps us look at what conditions were like before we started global warming, and what the natural variability was," said Jim Overland, a Seattle-based oceanographer for the National Oceanic and Atmospheric Administration who was not involved in Stern's project.

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Venus-like greenhouse effect? Global world temperature might rise over 7˚C within 100 years

Venus-like greenhouse effect? Global world temperature might rise over 7˚C within 100 years | Amazing Science |

Global mean surface temperatures are rising in response to anthropogenic greenhouse gas emissions. The magnitude of this warming at equilibrium for a given radiative forcing—referred to as specific equilibrium climate sensitivity (S)—is still subject to many uncertainties. A team of scientists now estimate global mean temperature variations and S using a 784,000-year-long field reconstruction of sea surface temperatures and a transient paleoclimate model simulation. Their results reveal that S is strongly dependent on the climate background state, with significantly larger values attained during warm phases. Using the Representative Concentration Pathway 8.5 for future greenhouse radiative forcing, they find that the range of paleo-based estimates of Earth’s future warming by 2100 CE overlaps with the upper range of climate simulations conducted as part of the Coupled Model Intercomparison Project Phase 5 (CMIP5). Furthermore, they find that within the 21st century, global mean temperatures will very likely exceed maximum levels reconstructed for the last 784,000 years and could rise up to 7 degrees centigrade. On the basis of temperature data from eight glacial cycles, these results provide an independent validation of the magnitude of current CMIP5 warming projections.

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Record-setting global temperatures will soon be the new normal

Record-setting global temperatures will soon be the new normal | Amazing Science |
The record-setting global temperatures seen in 2015 could be the “new normal” as soon as the 2020s.


The sweltering heat that smashed temperature records in 2015 will soon be par for the course. Depending on how much more carbon dioxide humans dump into the atmosphere, 2015 could become the “new normal” for global temperatures as soon as the 2020s, researchers estimate online November 4 in the Bulletin of the American Meteorological Society. Even if there’s a sharp reduction in CO2 emissions, the record-setting year (SN: 2/20/16, p. 13) will seem typical by 2040.


Those predictions are based on defining “new normal” — previously an informal term — as a point in time when at least half of the following 20 years surpass the record. Climate scientist Sophie Lewis of Australian National University in Canberra and colleagues applied their new definition to several simulations of future climate.


When 2015’s record heat is the new normal, extremely hot years will be beyond anything humans have encountered so far, the researchers predict. That extreme heat could lead to more deadly heat waves (SN: 9/3/16, p. 5), wildfires (SN Online: 7/15/15) and other climate-related disasters.

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Wildlife in decline: Earth's vertebrates fall 58% in past four decades

Wildlife in decline: Earth's vertebrates fall 58% in past four decades | Amazing Science |
Living Planet Report predicts that by 2020, populations will have declined by two-thirds from 1970.


The populations of Earth’s wild mammals, birds, amphibians, fish and other vertebrates declined by more than half between 1970 and 2012, according to a report from environmental charity WWF and the Zoological Society of London (ZSL).


Activities such as deforestation, poaching and human-induced climate change are in large part to blame for the decline. If the trend continues, then by 2020 the world will have lost two-thirds of its vertebrate biodiversity, according to the Living Planet Report 2016. “There is no sign yet that this rate will decrease,” the report says.


“Across land, freshwater and the oceans, human activities are forcing species populations and natural systems to the edge,” says Marco Lambertini, director-general of WWF International.

Via Dr Alejandro Martinez-Garcia
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Great Barrier Reef pronounced 'almost dead' by scientists 

Great Barrier Reef pronounced 'almost dead' by scientists  | Amazing Science |

A scientist who recently visited the Great Barrier Reef has said "if it was a person, it would be on life support", as researchers strive to highlight the plight of the reef. New images have shown the worrying extent of the damage done to the reef by climate change. Rising water temperatures have damaged the world’s largest reef system, which stretches for over 1,400 miles off the coast of Australia.


In May, researchers found that more than a third of the coral in northern and central parts of the reefs was dead, and 93 per cent of individual reefs had been affected by a condition known as coral bleaching.


This usually leads the corals to die as it ends their symbiotic relationship with algae-like single cell protozoa, which are expelled when corals are exposed to water which is too warm.

Scientists have found that the situation has worsened.


Amanda McKenzie, CEO of the Australian Climate Council, toldABC: "After the bleaching event in May, 60 per cent of what we saw was bleached very white. "Another 19-20 per cent was covered in sludgy brown algae. Even of what remained healthy, some looked a bit on edge. "When we went back a few weeks ago to see if they  had recovered or died, quite a large proportion had died."


She estimated around half of the bleached corals they visited had died, and that the bleaching had mostly affected delicate corals rather than the stronger 'brain corals'.


However, the researchers discovered that fewer species of fish were found on the reef.

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NASA says Earth is warming at a rate 'unprecedented in 1,000 years'

NASA says Earth is warming at a rate 'unprecedented in 1,000 years' | Amazing Science |

New data has confirmed that the Earth has been experiencing the hottest temperatures on record. The latest findings from NASA’s top climate scientists now reveal the world is heating up at a rate that hasn’t occurred within the past 1,000 years.


According to NASA, the planet will continue to warm “at least” 20 times faster than the historical average over the next 100 years. Gavin Schmidt, director of Nasa’s Goddard Institute for Space Studies, said that “in the last 30 years we’ve really moved into exceptional territory.” He added, “It’s unprecedented in 1,000 years. There’s no period that has the trend seen in the 20th century in terms of the inclination (of temperatures).”


July 2016 was the hottest month on record, and this year the average global temperature peaked at 1.38˚C above levels reported in the 19th century. That number is dangerously close to the 1.5C limit determined by the Paris Climate Agreement. Nasa warns that temperatures will only increase by leaps and bounds at the rate we are going.


If we have even the slimmest of hopes to combat this unprecedented rate of global warming, Schmidt says, “maintaining temperatures below the 1.5˚C guardrail requires significant and very rapid cuts in carbon dioxide emissions or co-ordinated geo-engineering. That is very unlikely. We are not even yet making emissions cuts commensurate with keeping warming below 2˚C.”


“It’s the long-term trend we have to worry about though and there’s no evidence it’s going away and lots of reasons to think it’s here to stay,” Schmidt said. “There’s no pause or hiatus in temperature increase. People who think this is over are viewing the world through rose-tinted spectacles. This is a chronic problem for society for the next 100 years.”

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The trillion dollar question nobody is asking the presidential candidates

The trillion dollar question nobody is asking the presidential candidates | Amazing Science |

As it seeks to modernize its nuclear arsenal, the United States faces a big choice, one which Barack Obama should ponder before his upcoming Hiroshima speech. Should we spend a trillion dollars to replace each of our thousands of nuclear warheads with a more sophisticated substitute attached to a more lethal delivery system? Or should we keep only enough nuclear weapons needed for a devastatingly effective deterrence against any nuclear aggressor, investing the money saved into other means of making our nation more secure? The first option would allow us to initiate and wage nuclear war. The second would allow us to deter it. These are very different tasks.


As physicists who have studied nuclear reactions and cataclysmic explosions, we are acutely aware that nuclear weapons are so devastating that merely a hundred could annihilate the major population centers of any potential state enemy. That prospect is enough to deter any rational leadership while no number of weapons could deter a mad one. Waging nuclear warfare could involve using vastly more warheads to strike diverse military and industrial targets.


The U.S. and Russia currently have about 7,000 nukes each, largely for historical reasons. That’s over 13 times as many as held by the other seven nuclear powers combined. When the Soviet Union was perceived to be a threat to Europe with its numerically superior conventional forces, the U.S. stood ready to use nuclear weapons in response. We were prepared not only to deter the use of nuclear weapons by others, but also possibly to initiate nuclear warfare, and to use nuclear weapons in battle.

Now the tables have turned and NATO is the dominant nonnuclear force in Europe. But other arguments for maintaining the ability to initiate nuclear war remain, positing the utility of “compellance” (also known as “nuclear blackmail”) or using the threat of nuclear attack to extract concessions. This strategy has been used on several occasions. For example, when President Eisenhower threatened the use of nuclear weapons to compel negotiations ending the Korean War.


In today’s world, with nuclear technology more widely accessible, compellance is no longer straightforward. If a nonnuclear nation feels it is subject to nuclear bullying, it can counter by developing its own nuclear deterrent, or enlisting nuclear allies. For example, U.S. nuclear threats inspired North Korea to mount its own nuclear program, which is, to say the least, not the result we were hoping for.

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Human-Induced Climate Change Blamed for Half of Increased Forest Fires

Human-Induced Climate Change Blamed for Half of Increased Forest Fires | Amazing Science |

Forest fires are burning longer and stronger across the western United States, lighting up the landscape with alarming frequency. Residents are forced to flee, homes are incinerated, wildlife habitats are destroyed, lives are lost. Last year, the Forest Service spent more than half its annual budget fighting fires.


Scientists have long theorized that climate change has contributed to the longer fire seasons, the growing number and destructiveness of fires and the increasing area of land consumed, though some experts suggest that the current fire phenomenon is not just a result of a changing climate, but also fire-suppressing policies practiced by the government for the last century or more.


In a new study published Monday in Proceedings of the National Academy of Sciences, scientists from the University of Idaho and Columbia University have calculated how much of the increased scope and intensity of Western wildfires can be attributed to human-caused climate change and its effects. They state that, since 1979, climate change is responsible for more than half of the dryness of Western forests and the increased length of the fire season. Since 1984, those factors have enlarged the cumulative forest fire area by 16,000 square miles, about the size of Massachusetts and Connecticut combined, they found.

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Deepest Underwater Cave Discovered

Deepest Underwater Cave Discovered | Amazing Science |
Czech abyss is so deep the Empire State Building could fit inside.


A team of explorers has found the deepest underwater cave yet discovered, with a bottom that lies at least 1,325 feet below the water's surface. Polish explorer Krzysztof Starnawski, who led the team, first explored the cave -- named Hranická Propast and located near the Czech town of Hranice -- in 1999, and instantly knew it was an unusual find. He told National Geographic, which sponsored his most recent expedition, that hot water saturated with carbon dioxide bubbled up like a volcano, and made his exposed skin itch.


A series of dives over the years hinted at the abyss' depth. In 2014, he reached 656 feet, thinking he had found the bottom, only to discover a very narrow opening that led to a vertical tunnel. The following year, some of the rock in the cave had crumbled, widening the opening and making it possible for him to squeeze through. He reached a depth of 869 feet and released a probe, which at 1,214 feet landed on what was probably a pile of debris from the collapsed passage above.

Via Kathy Bosiak
Donavon's comment, October 3, 2016 4:00 PM
summary~That's cool. What did they build it out of to withstand that dept? Looks like that 39 ft helped. This article is short. I would be scared to go down that deep. Did they find anything cool down there?
Donavon's comment, October 3, 2016 4:01 PM
comment~Like i said
Donavon's comment, October 3, 2016 4:04 PM
comment~Like i said i would be scared to go down that deep. What if something went wrong. I can't hold breath that long. I doubt that anything lives down there. But what if they did.
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Data center emissions rival air travel as digital demand soars

Data center emissions rival air travel as digital demand soars | Amazing Science |

Watching another episode on Netflix, reading the Guardian online and downloading apps are not obvious ways to pollute the atmosphere. But collectively, our growing appetite for digital services means the data centers that power them are now responsible for about 2% of global greenhouse gas emissions, a similar share to aviation.


Varying from a small room with servers to vast farms with a floor area of 150,000 square meters, data centers are big energy users. As well as requiring power to run the equipment that stores and serves us cloud computing and on-demand music, films and entertainment, those servers also generate a lot of heat and require huge amounts of energy to keep them cool. That’s why big data users such as Facebook are siting their centers in cool climates such as northern Sweden.


Individually, our everyday browsing has a relatively minuscule impact. Google, in response to claims that each search on its site generated as much CO2 as boiling half the water for a cup of coffee (7g), calculated the true figure was much lower, at 0.2g. Watching a YouTube video of cats was higher – 1g for every 10 minutes of viewing – while using Gmail for a year produced about 1.2kg a user.


Not to be outdone, Facebook put a figure on its average user’s annual footprint – 269g of CO2, roughly equivalent to the carbon footprint of a cup of coffee. But with the technology giants’ billions of users worldwide, those numbers scale up quickly. Google’s carbon footprint was 1,766,014 tons CO2 equivalent in 2013, and the bulk of that was from data centers.


As with emissions from air travel, the real issue with data centers is the rate at which they are growing.  “It’s an exponential growth in data,” said Sophia Flucker, director at Operational Intelligence, a UK-based consultancy that advises data centers on their energy use. “Although IT efficiency is improving, and we can do more with less power, the demand is still there,” she said. “Any efficiency gains are being eaten up by demand. It’s very much an upward trajectory.”

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